1. Field of the Invention
This invention generally relates to a derailleur for a bicycle. More specifically, the present invention relates a derailleur for a bicycle that can be easily disassembled for replacing the parallel links.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One part of the bicycle that has been extensively redesigned is the drive train of the bicycle.
Most of today's bicycles are multi-speed bicycles that allow the rider to select the appropriate gear ratio to suit the particular riding conditions encountered during the bicycle ride. One of the most popular types of gearing assemblies for multi-speed bicycles utilize a chain extending between a set of front sprockets mounted for rotation with the pedals and a set of rear sprockets mounted on the rear hub of the rear bicycle wheel for rotation therewith. A front derailleur is used to move the chain between the front sprockets or gears. Generally, most derailleurs (front or rear derailleurs) include a fixed member nonmovably secured to a bicycle frame, and a movable chain guiding member supported for movement relative to the fixed member. The chain guiding member has a pair of guide plates that forms a chain receiving slot for contacting and moving a chain between the sprockets. In the case of a rear derailleur, sprockets are rotatably mounted between the guide plates.
Normally, the front derailleur is designed to hold the chain on the inner sprocket, i.e., the sprocket closest to the center of the bicycle. The rear derailleur, on the other hand, is normally arranged to position the chain on the outermost sprocket in its rest position. In other words, when the rider operates the shift operating device of the front derailleur shifting mechanism, the operating conduit or cable pulls the front derailleur such that the chain is moved outwardly from one gear or sprocket to the next gear or sprocket, or releases the front derailleur such that the chain is moved inwardly from one gear or sprocket to the next gear or sprocket. When the rider operates the shift operating device of the rear derailleur shifting mechanism, the operating conduit or cable pulls the rear derailleur such that it moves the chain inwardly from one gear or sprocket to the next inner gear or sprocket, or releases the rear derailleur such that it moves the chain outwardly from one gear or sprocket to the next gear or sprocket. In other words, when the shift operating devices are moved to release the derailleur, the front derailleur will move inwardly towards the center of the bicycle, while the rear derailleur will move outwardly away from the center of the bicycle.
The front and rear derailleurs are constantly being redesigned to operate more efficiently and to improve the design such that they can be made lighter. Accordingly, derailleurs are typically constructed of lightweight materials and are made as thin as possible. Of course, this can result in the parts wearing out at a faster rate. Therefore, it is desirable to reduce wear in the more expensive parts of the derailleur or the more difficult parts to remove. Moreover, it is desirable to design the derailleur such that parts can be easily removed for cleaning and/or replacement.
In view of the above, there exists a need for a derailleur for a bicycle which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.